Surface plasmon resonance phenomenon is that when a light source illuminates a metal surface at a fixed incident angle, the reflection intensity detected by a light detector would be near zero, which means the reflectivity of the metal film is near zero. The light which is not reflected will propagate along interface direction at a certain velocity to resonantly excite the surface plasmon of the metal. The method of measuring the reflected light is known as Attenuated Total Reflection (ATR).
A surface plasmon resonance sensing system uses a sensing system made by surface plasmon resonance phenomenon. Because the surface plasmon resonance sensor has high sensitivity, is label-free for detecting molecules, and can analyze the interaction between molecules at real-time. Other advantages include short analysis time and capability of simultaneous parallel detection. The system is therefore in widespread use on detecting biomolecules.
Recently, the development of nanomaterials is applied to optoelectronics, communication and medical equipment. Nanomaterials may provide specific characteristics which completely differ from traditional materials. The localized surface plasmon resonance (LSPR) associated with gold nanoparticles is utilized to replace propagating surface plasmon resonance (PSPR) associated with traditional gold thin film. The sensitivity of the sensor is still good and other features such as pixel size and simplicity in construction of the sensor are then improved. The approach of synthesizing nanoparticles has chemical and physical ways. The physical way includes metal vapor deposition, laser ablation, and sputtering, wherein the metal vapor deposition is frequently used. The chemical way includes reduction method and electrolysis method. The reduction method is frequently used, and is also the most important way. However, when the technology is increasingly developed, the sensitivity of the sensor needs to be further improved.
To further improve the sensitivity of the sensing system, the inventor of the present invention based on years of experience to conduct extensive researches and experiments invents a surface plasmon resonance sensing system and method thereof, as a method or a basis for achieving the aforementioned object.